Tractor transmission mechanism



L. H. KEHVI.

TRACTOR TRANSMISSION MECHANISM.

APPLICATION FILED FEB 1, 19|8.

1,431,959, Patnted Oct. 17, 1922.

/ ATfORNE Patents oa. inf i922.

, innate sari-tr QFIFHGEO LESTER 'H. KEIM, or CHICAGO, ILLINOIS,.assronon To a. D. NUTTALL comrenv, a

I oonrona'rron orrnnnsvnvnnra.

=. frnncron TRANSMISSION MECHANISM.

' Application filed February 1, i91a. Serial 110.21%,811.

To all whom it may concern; J

Be it known that I, LESTER H. KEIM, a

citizen of the United States, and a resident of Chicago, in the countyof Cook and State of Illinois, haveinvented a .new and usefulImprovement in Tractor Transmission Mechanisms, of which the followingis a specification. p 1

This invention relates to transmission mechanisms particularly adaptedfor heavyduty vehicles, such as tractors and trucks, but it is to beunderstood that certain features may be embodied-in other motor-drivenvehicles. I The principal object of the. present invention is to providea compact, rugged transmission mechanism in which the .changevide a wellbalanced change-speed and transmission unit in which the driving shaftprojects from opposite sides of the transmission casing for connection,at one end, to a pulley and-at the other end to an internal-combustionengine.

Another object of the invention isto provide a reduction gearing of aslarge a ratio as possible, and toaccomplish this I employ helicalgearing for transmitting the power from the counter-shaft to the drivenaxles.

The above and other objects and the novel features of my invention willbe apparent from the foregoing description taken in connection with thedrawing constituting a part of this application and in which the singlefigure is a horizontal sectional view of a transmission mechanismembodying my invention.

The invention is shown as designed for embodiment in a gas-engine-drivenfarm tractor, but it is,to be understood that certain features thereofare not limited to this application but may 'be applied to other typesof transmission mechanisms and vehicles. A transmission casingC, thatencloses the change-speed and the differential axially of the drivinmechanismv is supported at its rear end by.

an axle A and traction wheels W.

The casing C is substantially rectangular .and trough-shaped and has Iparallel side walls 12 and 13, end walls '14 and 15 and a bottom wall 16which latter merges into the end walls 14: and 15. The side walls 12 and13 have two oppositely disposed openings 121 and 131 therein, at thefront end of the casing, to receive the bearing caps 17and 18,

I the casing and projects through the open-' speed mechanism, reversingmechanlsm and differential are completely enclosed within a ings 172 and182 in the caps 17 and 18. An internal-combustion engine E is mountedupon a vehicle frame (not shown), and has its shaft extendingtransversely of the longitudinal center line of the vehicle, the enginetransmission shaft being connected to the driving shaft 21 through asuitable clutch and other parts (not shown) enclosed within a housing H.The end of the driving shaft 21 that projects from the other side of thetransmission case C has a pulley P mounted thereon which is adapted tobe belted to farm machinery when the vehicle is stationary.

The high-speed pinion 23 and the lowspeed pinion 24 are splined on, thedriving I shaft 21 within the casing C and are movable the lower forkedends of shifters (notshown).

The high and low-speed gears 25 and 26 have hollow hubs surrounding theends of a sleeve 36 that is rotatably supported on bearings '37 whichare mounted on a countershaft 38. The ends of the shaft 38 fit inopenings in the side walls of the casing C and the shaft is heldstationary by means of a set screw 39. The length of the sleeve 36 isslightly less than the distance between the side walls 12 and 13, asmall clearance being allowed at each end. At opposite sides of itscenter, the sleeve is provided with shoulders 40 against which the hubsof the gears 25 and 26 abut. The central part of the sleeve is enlargedand provided with double-helical teeth to form a pinion 41 that shaftinto, and out are is integral with the sleeve and will rotate with thegears 25. and 26. r 7

Near its rear end, the casing C is provided with two oppositely disposedopenings 42 and 43 to receive portions of the sleeves 44 I and 45 thatsurround the driving axles 46 and 47 and carry the bearings therefor.The

pinion41 is constantly enmeshed with a suitable external double-helicalgear 48 that is bolted by bolts 491 to the rim of a differential spiderS and to the differential side plates 49. The differential sideplates-also enclose rotatable differential bevel pinions 50 that arecarried by the spider S- and mesh with the two differential bevel gears51 and 52 located at opposite sides of the differential spider S. Thebevel gears 51 and are provided with elongated cylindrical hubs 511 and521 that surround, and are keyed to, the driving axles 46 and 47,respectively. The hubs 511 and 521 are respectively supported bybearings 512 and 522 carried, respectively, by the flanges 441 and 451at the inner ends of the sleeves 44 and 45, and longitudinal movement ofthe differential housing, bearings 512 and 522 and the hubs 511 and 521is limited by the flanges 442 and 443 that extend inwardly, at rightangles, toward the axles from the bases of the flanges 441 and 451. Aspacer ring 53 is disposed between the inner ends of the axles 46 and 47and the inner ends of-.the hubs 511 and 521. The inner ends of thesleeve 44 and 45 are bolted to the casing C, and the outer ends thereofare secured to the side members of the frame F and enclose bears ings 54and 55 that carry the axles 46 and 47. Caps 56 and 57 are bolted to theends of the sleeves 44 and 45 and are provided with central openingsthrough which the axles 46 and 47 project. The outer ends of the axles46 and 47 project into the hollow hubs h of the tractor wheels W and arerigidly keyed thereto. Theaxles 46 and 47 have reduced threaded ends 581to receive the hub caps 582 which overlap the ends of the axles and theportions of the hubs l2. and

hold the wheels W against the ends of the sleeves 461 and 471.

The operation of the speed-change transmission mechanism will beapparent from the foregoing description. The low-speed pinion 24 isadapted'to be moved into mesh with the low-speed gear 26, or thehighspeed pinion 24 may be enmeshed with the high-speed gear 25, eitherof which will drive the pinion sleeve 36 carrying the pinion 41 so as topro el the vehicle in a forward direction. '1- e speed-changetransmission is thus capable of adjustment to two speeds forward.

The pinion 41 and the differential gear 48 are symmetrically locatedwith respect to the longitudinal central plane of the vehicle end of thetransmission case C to provide a more pinion-and-gear reduction gearingbetween the drivingshaft and rear drive axles. This is because I mayemploy a helical pinion of a finer pitch, less diameter and less widthof face, Without reducing. the strength of the possible size of spurpinion for transmitting the same power. Furthermore, with a given numberof teeth on the driving pinion,.the helical gear mating therewith mayhave more teeth than the gear of a spur pinion-- and-gear drive, whichalso results in a greater speed reduction.- In this construction, thefaces of the gear and pinion may be narrower than the faces of a spurgear and pinion for the same purpose, thus effecting a saving in theweight of the gearing.

While I have shown and described the construction and arrangement indetail, it will be apparent that various changes may be made withoutdeparting from my invention, as expressed in the appended claims. 7 Iclaim as my invention:

1. In combination, in a transmission mechanism, a gear casing havirjig aplurality of pairs-of oppositely ispose openings in 1ts side walls, adriving shaft journalled in a pair of said openings, a driven shaftjournalled in another pair of said openings, speed-changing andreversing gears carried by said shafts, a differential mechanismoperatively connected to a inion on said driven shaft and having t 'edriven gear wheels thereof provided with extended hub portions, a pairof oppositely extending axle members extending through the walls ofthecasing, road wheels secured to the axle members, sleeves surroundin saidaxle members and provided with ax e-bearing supports, means forsupporting the differential mechanism directly upon the saidaxle-bearing supports, and means whereby the sleeves are secured to thecasing, and. a differential-gear housing superposed upon the said hubportions.

2. In combination, in a transmission mechanism, a gear casing, atransmission mechanism mounted in the casing, a driving memher, adifferential mechanism operatively connected to said transmissionmechanism and having the driven ear wheels thereof provided withextendedv ub portions, a pair of oppositely-extending sleeve memberssecured to the casing, a pair of oppositelydisposed axle .membersextending into the sleeve members and operatively connected to thedifferential mechanism, axle-bearing pinion and its teeth below that ofthe lowest of axle members exten ing supports carried within the sleevemembers and serving also as. bearings for the said hub portions, and aroad wheel connected to each of the axle members at its outer end.

3. In combination, in a v transmission mechanism, a gear casing, atransmission mechanism secured therein, means for driving thetransmission mechanism, a dilferen- 'tial mechanism also carried withinthe casing and having the driven gear wheels thereof provided withextended hub ortions, a pair of oppositely-disposed sleeve memberssecured to the casing," a bearing on the inner end of each sleeve memberby which the 'difi'erential mechanism is directly supported, throu bsaid hubs a pair into the sleeve members and each having its inner endoppositely connected to the differential mechanism and supportedadjacent its outer end in a bearing carried within its associated sleevemember, and a road wheel secured to the outer endof each axle member. I

4. In combination, in a transmission mechanism, a gear case providedwith aplurality of openings in its side walls, a driving shaft, adifferential mechanism 'operativeiy connected to the driving shaft andcomprising beveled pinions and gear Wheels, a pain of oppositelyextending axle members extending through the walls of the casing, andsleeves surroundingvthe axle members and provided with supports for theinner ends of the axles, the diiierential gear wheels havingextended hubportions and the said supports serving also as bearings for the said hubortions.

5. n combination, in a transmission mechanism, a-gear case provided witha plurality of openings in its side walls, a driving shaft, adifferential mechanism operatively connected to the driving shaft andhavin its driven gear wheels formed with extended hub portions, a pairof oppositely extending axle membersextending through the walls of thecasing, and sleeves surrounding the axle members and provided withbearings for the said extended hub'portions.

In testimony whereof, I have hereunto subscribed my name this 15th dayof-Jair,

LESTER H. KEIM.

